X-brace screen



Aug. 6, 1963 F. B. OLENDER ET AL X-BRACE SCREEN 2 Sheets-Sheet 1 Filed Feb. 1, 1961 FIG. 7.

FIG. 2.

INVENTORS Francis B. Olender Albert Wilson ATTORNEY Aug. 6, 1963 F. B. OLENDER ET AL 3, 00,189

X-BRACE SCREEN Filed Feb. 1, 1961 2 Sheets-Sheet 2 62 FIG. 5.

FIG. 6.

INV EN TORS Francis B. Olender Albert Wilson ATTORNEY United States Patent 3,100,189 X-BRACE SCREEN Francis B. (blender, Wellington, and Albert Wilson, Garfieid, Ni, assignors to Hewitt-Robins Incorporated, Stamford, Conn.

Filed Feb. 1, 1961, Ser. No. 556,347 1 (Ilaim. (1. 209-409) This invention pertains to vibrating screen devices useful for sizing or separating materials, as well as for conveying. The invention more particularly relates to a screen construction having improved rigidity and more controllable characteristics.

Screens of the type to which this invention relates comprise a pair of spaced parallel side frames or plates. These are interconnected by cross bracing devices and the screen is supported upon the latter devices intermediate the two plates. Usually supporting members are placed on top of the cross bracing members that interconnect the side plates and wire screening members are mounted on these supporting members. The screening devices or screens obtain their name from these screening members. Often these are made of wire mesh. The wire screening members are grasped at their sides by clamping devices which attach them to the side frames or plates of the screen device.

A screen device of the type to which the instant invention relates is shown in U.S. Patent 1,693,940. It will be noticed, in the latter patent, that the screen device is crossbraced by members which extend substantially transversely between the side plates. Experience has shown, however, that such construction is not entirely satisfactory. This can be appreciated from a study of the particular structure of the prior known devices.

As can be noted from the instant drawings, as Well as from the above patent, the screen device comprises some form of mechanism for creating a vibration within the screen. Usually this is an eccentrically loaded device which is rotated, and which is journaled in the screen side plates. The side plates and the screen oscillating or vibrating means are mounted on supports designed to permit movement thereof by the vibrating mechanism. For example, they may be supported on cables from overhead or they may be supported on springs upon the floor. Both means of support are well known in the art. The vibrating mechanism thus transmits its forces through the side frames and the connected cross-bracing and these elements move with the vibrating mechanism.

Screens thus constructed are subject to a form of improper openation which generally has been termed by many as off motion. This is a condition due to oif balance of the counter-weights, or the springs or other supports not being in uniform condition, or unequal loading. it is, in fact, difficult to produce a system in which everything is accurately balanced. As a result of this ottmo-tion there is often a tendency of one side frame to move relative the other side frame. Heretofore known interconnecting structure or brace construction has lacked the torsional rigidity needed to prevent such 01f motion. In fact, even though in many instances the laterally extending bars, such as the type shown in the above mentioned patent, have been augmented by plates and other devices, there is still encountered, in many instances, a

serious oft-motion. This motion can be damaging to the screens. It usually results in an improper operation. Accordingly, one object of our invention is to overcome these disadvantages.

As indicated above, in the past attempts have been made to cure off motion and similar problems by adding brace means. However, the adding of diagonal bracing in addition to the regular laterally extending brace members and the addition of gusset plates for interconnecting these members to the side frames increases the cost of the screens. Further, these plates and similar structure decrease the effective area of the screen. The more cross-bracing employed the less effective the screening area. Accordingly, another object of this invention is to provide a more efiective means of interconnecting the side frames of a screen and yet retain maximum efiective screen area.

Still another object is to provide a cross-bracing structure whereby effective screen support can still be maintained.

Yet an additional object of the invention is to provide a means of greatly reducing the cost of construction of screens yet obtaining even better stability and performance characteristics than heretofore possible.

Another object of our invention is to provide a simplified means of connecting the bracing to the side frame structure, thus greatly facilitating construction and reducing the cost of fabrication. Other objects include that of providing a bracing structure which can be readily formed of commercially available shapes with a simplified manufacturing method. A still further object is to provide exceptional torsional rigidity as compared with heretofore known screen cross bracing.

These and other objects and advantages will become apparent from the following description and the accompanying drawings wherein:

FIGURE 1 is a perspective view partly in section showing a screen embodying our invention.

FIGURE 2 is atop plan view of a portion of the screen on an enlarged scale.

FIGURE 3 is a side elevation of the structure shown in FIGURE 2.

FEGURE 4 is an enlarged perspective view of a brace member constructed in accordance with the invention.

FIGURE 5 is a fragmentary top plan View showing another form of brace constructed in accordance with the invention.

FIGURE 6 is a side elevational view of the latter brace.

FIGURE 7 is a diagrammatic view illustrating an offmotion condition or effect.

As mentioned heretofore, it is important that screen side frames be maintained in true parallel relationship with respect to each other and that they do not gallop or twist. If they do there is great likelihood of structural damage and the desired screen motion is lost. According to our invention we solve this problem. It should be also noted that one of the advantages of the instant in vention is that we provide a cross-brace structure which can be pre-assembled as unitary elements and then direotly connected to the side plates in a single operation. Another advantage of our invention is that we can elimina-te welding of brace means to the side plates and utilize an assembly technique which reduces the time and labor needed.

Referring now in particular to the drawings: the screen constructed in accordance with the invention comprises a live frame 19. This is a moving frame; i.e. a vibrating frame. It is supported upon spring devices 12. A vibration mechanism is enclosed within the structure generally indicated by the reference character 14. These structures are well known in the art and they are thus only represented schematically in the drawing. The live frame has two opposite side plate members 15 and 16. These two members must be interconnected and the connecting means must provide a support for the wire mesh screen 18. The driving means for creating the oscillations of this frame structure are referred to in the claim simply as means, but are not described or shown in detail as they are well known and old in the (See the above mentioned patent for an example.)

According to our invention we provide a cross bracing structure consisting of pre-fabricated braces 20. Each brace comprises a central section 22 and leg portions 24, 26, 28 and B0. The leg portions 24 and 26 extend outward from one side of the central section and the leg portions 28, 30 extend outwardly from the other. Further, on each side of the central section the respective leg portions diverge outwardly with respect to each other to form a V-like configuration. The leg portions and the central section are in the same plane. Also, it should be noted that each leg portion on one side of the central section is substantially in alignment longitudinally with a leg portion on the opposite side of the central section. Thus leg portion 24 is substantially in alignment with the leg portion 30'. Each of the leg portions has, at its end, an abutment plate 32, 34, 3 6, and 38 respectively. These abutment plates are adapted to be directly connected to the side frames 16 and 10 by bolts and nuts such as 40.

In the preferred form illustrated in the drawings the braces are formed out of two leg members, each of which comprises the leg portions such as 30 and 26 and a central portion 42. The leg portions and the central portions are formed by bending channel shaped members. Bending is accomplished so as to provide bases 44 adjacent the central section. The bases 44 on the opposite members are inter-connected by bolt and nut means. This results in a rigid interconnection of the two leg members and produces a fixed central portion for the brace without any welding or cutting.

It is only necessary to deform the channel members to produce the section elements. The abutment plates are attached to the leg portion, however, by welding. It is noted that the webs 46 and flanges 48 and G retain their normal relative position throughout the legs.

In assembling a screen the braces 20 are performed and, as is apparent, are readily attachable to the plates and 16 so as to fix the latter two plates in proper relationship. Adjacent braces are abutted through their abutment plates 32 and 36 as indicated at 52 in FIGURE 1. This results in a succession of braces extending lengthwise of the screen which form a rigid, continuous frame extending length-wise of the screen. The braces are interconnected by their abutment plates and the side plates themselves form, in actuality, a portion of the continuous frame at the point of connect-ion of the abutment plates to the latter. Assemblage of the screen units is, obviously, relatively simply accomplished.

FIGURE 7 illustrates schematically, in an exaggerated manner, an off-motion effect in the screen. It is to be noted that one plate '54 has angled with respect to the opposite plate 56. This, of course, produces variable screening elfect across the surface of the screen and in some areas no effective screening is accomplished at all when such a condition exists. The screen must move in the path pre-determined for the most efiicient operation or else it will not be as effective as it had been designed to be, or intended to be. FIGURES 5 and 6 illustrate another form of brace member constructed according to the invention. in this form the two-leg portions 58 and 60 are provided with a common abutment plate 62. When there braces are interconnected the adjacent abutment plates on adjacent braces abut each other and are interconnected by means of the side frame. This produces a continuous frame element extending along the two plates, in addition to the frame elements which the plates themselves constitute.

FIGURE 4 serves to illustrate an important feature, as well as a principle utilized in our invention. Arrow 64 indicates a line of action such as often effected in a common screen device. If shaken or agitated, primarily along this or a similar line, the screen device will advance the material as it is screened. Arrows 66 and 63 respectively indicate the vertical and horizontal component of this motion. Arrows 70 and 7-2 indicate force transmission (components) of the horizontal force 68 through the brace means. Thus there is achieved an inherent rigidity not possible with previously known structures. The divergent leg portions being in the horizontal plane transmit the horizontal forces along their lengths and do not resist such primarily in torsion. T hus not only does the brace have inherent torsional rigidity far above that of simple lateral members, but each leg member in itself is more properly positioned to resist twisting. Twisting must occur to elfect the movement illustrated in FIGURE 7. The leg portions can be angled relative to each other in selected manners according to the screen design. Thus they can be adapted to a particular stroke pattern or line of action in a manner most likely to achieve maximum utilization of their strength.

From the foregoing it will be apparent that we have provided a screen construction which rigidly interconnects the side plates and presents a continuous box-like frame extending length-wise of the screen. From tests of units actually embodying the instant invention it has been found that the off-motion characteristics heretofore found in other screens have been eliminated to a substantial degree. Side frame parallelism and screen activation are maintained more satisfactorily with this construction.

While we have shown and described a preferred form of our invention, it will be understood by those skilled in the art that many changes in details and forms may be made within the scope of the appended claim, and accordingly we claim an exclusive right to all which come within the scope of the appended claim.

We claim:

In a vibrating screen, a pair of vertically disposed parallel side plates, brace means interconnecting said plates, said plates being adapted to have a means associated therewith for moving said plates and said brace means in a manner so as to have a selected motion to elfect a selected screening operation, which motion has vertical and horizontal components, said brace means comprising a pair of channel-shaped members, the web of each channelshaped member facing the web of the other member and being in contact with and connected to the web of the other member along a relatively short length of the channel as compared to the total length thereof, the flanges of one of said channel members extending outwardly in opposite direction from the flanges of the other of said channel members, the Webs of said channel members being vertically disposed, said channel members forming diverging leg portions extending outwardly from opposite sides of the contacting length of said channel members in a plane transverse to said webs, said leg portions forming substantially an X-shaped brace of said connected channel members, each leg portion of each channel to one side of the connected portions of said webs being substantially in alignment with a leg portion of the other channel on the opposite side of said connected portions of said webs, said X-shaped brace having abutment plates at the ends of said leg portions securing said X-shaped brace to said side plates with one leg portion of each channel member being connected to one of said side plates and the other leg portion being connected to the other of said side plates, said leg portions of at least one of said channel members extending in a horizontal plane in directions which result in transmission of the horizontal component of the forces resulting from the screen motion, along the latter legs, from substantially the center of said screen to said side plates.

References (Jited in the file of this patent UNITED STATES PATENTS 862,973 Kahn Aug. 13, 1907 6 Mager Jan. 30*, 19 12 McWain Mar. 2, 1926 Van Ranst Jan. 1-9, 1932 Robins Aug. 22, 1933 Dietrich Nov. 5, 19'35 Almdale Sept. 30, 194-1 Holstein Aug. 17, 1943 Parks Apr. 4, 1944 Hess Sept. 2, 1952 FORETGN PATENTS Germany Aug. 31, 1935 

